Motion-picture apparatus.



C- F. JENKINS.

MOTION PICTURE APPARATUS.

APPLICATION FILED APR-6, 1916.

Patented June 12, 1917.

Q DU DO U D D @QQDDQDUQQD standard film. Fig. 2 is an end new of the special drum UNITED STATES PATENT OFF CHARLES FRANCIS JENKINS, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO THE GBAPHOSGOPE COMPANY, 0] WASHINGTON, DISTRIGTOF COLUMBIA, A QOB- IORA'IION OF DELAWARE.

To all 'wkom it may concern:

Be it known that I, CHARLES Famous JENKINS, a citizen of the United States, residing 'at Washington, in the District of Columbia, have invented certain new and useful Improvements in Motion-Picture Apparatus, of which the following is a specification, reference being had therein to the accompanying drawing.

The object of this invention is to provide for the use of the same special motion picture film in either a machine which uses standard film or in one in which standard film cannot be used.

It is well known that in general standard, highly inflammable motion picture cannot now be used outside of a practically fireproof cabinet, and that the same restrictions apply to the use of any machine adapted to feed such standard film. Slow-burning film may be used in a special machine incapable of feeding standard film, and without infringing upon any insurance or municipal rules or regulations, and, for example, suchmachine or film may be used in any room or may be removed from room to room in any school or dwelling as often as may be desired. Heretofore, so far as I am aware, this plan has involved providing a second film if it were desired to show the same reel or subject matter by using a stand-- ard machine, and as lon pensive and also heavy an so more or less inconvenient to carry about in large numbers, the saving of one of two reels is important. This invention involves the use of film so perforated that, it may be used in either a standard machine or in a special matzihine in which standard film cannot be use 1 In the accompanying drawings,

' Figure 1 shows a standard sprocket drum and an axially alined special drum having at regular intervals certain teeth of the standard drum replaced by special teeth which cannot enter the perforations of of'Fig. 1.

Fig. 3 shows parallel slightly separated portions of a standard film and a special iilm Ciidgapted for use with the drums of Figs. an z p I Specification of Letters Patent.

films are ex- Patented June 12, 1917.

Application filed April e, 1916. Serial No. sasza.

In these figures, A represents a standard sprocket drum and B a similar drum in which sets of standard teeth, shown as hav- 'ing two teeth in a set, alternate with special teeth C which in.this instance occupy pre-- cisely the same space as two consecutive standard teeth D plus the space between the two, so that the forward face of this long tooth lies in the plane which would be occupied by the forward face of the foremost regular tooth which is replaced. All the teeth are of substantially the same thickness,"

measured parallel to the drum axis.

Obviously the film E, Fig. 3, which is standard film, cannot be used on the special drum, since it has no long perforations to receive the long teeth C, but the special film F which has such long perforations may be so used and evidently may also be used on a standard sprocket drum, two consecutive teeth of which exactly fill the long perforation. 'One standard tooth and its forward face are lost, but-that is not ma terial since several teeth are at all times engaged.

The parallel lines w-zv, y'y, Flgs. 1 and 3, show to the eye that the long tooth occupies exactly the same space as two consecu-- tive standard teeth. It is not indispensable that there should be two teeth'in each set thereof, but each having its forward face precisely in the plane which would be occupied by the forward face of a tooth were all the teeth those of a standard sprocket drum.

2. A" film feeding sprocket drum having teeth of unequal circumferential extent, the forward faces of all being in position to engage the forward sides of the corresponding perforations of standard film.

3. A film feeding sprocket drum'having sets of teeth each in form and location like 4. Afilm having sets of standard perfothe corres onding teeth of standard film, rations, the sets alternating with perforathe sets alternating with teeth of greater tions each equal in linear extent to the space circumferential extent each having its foroccupied by a plurality of consecutive perward face in the plane which would be 00- forations of standard film.

cupied by the forward face of a standard tooth in a corresponding standard drum. CHARLES FRANCIS JENKINS. 

